Jaybird's official 2.7 rebuild thread

[Dick Shift]

You have a virgin case. Nothing appears to have been done to the head studs threads in the case. If you have no pulled studs you are starting with the best case scenario! Again I recommend 2nd oversize case savers if you can get them. ist over size will probably last for very long time as well if only option. Aloha

[dion914-6]

For comparison purposes, I just took a pic of my 7R case without the studs. I believe this is a virgin case too, but it does have the appearance of some kind of insert. Why would it look like this if the threads are machined into the case?

Dion

[dtw]

Agreed, that's a virgin case. Did you already start removing studs? A couple of the studs pictured are not threaded deep enough to be at 135mm.

A pic of a well-cleaned surface would really help clear this up.

[cgarr]

If you can get one stud out, stick a magnet down there and check the threads.

[dion914-6]

Originally Posted by cgarr

If you can get one stud out, stick a magnet down there and check the threads.

Confirmed, mine didn't stick to a magnet.

D

[jaybird840]

Is this trouble, or not????

[dtw]

What? You talking about the texture of the casting? No, no trouble.

[jaybird840]

When in doubt... SPLIT IT!!! Got pissed off over all the agony, and said to hell with it. Glad I did.



Looks like the main bearings have some discoloration or pitting from sitting up for several years, as well as a bit of scoring....



and now, the $25,000 question... are these standard, or oversize? If they're standard, I think I'll go ahead with the rebuild. If they're oversize, I've heard they're ungodly expensive, and I may part it out and go back to a stroker type 4.

[dtw]

That bearing actually looks pretty good, all things considered.

I can't find that part number - can you put a caliper on the bearing and give a measurement of the thickness?

[jaybird840]

Bearings measure 2.46 - 2.50 mm. or .096-.097" What do you think?

Originally Posted by dtw

That bearing actually looks pretty good, all things considered.

I can't find that part number - can you put a caliper on the bearing and give a measurement of the thickness?

[notmytarga]

the "00" at the end means -----> STD/STD

Have the case checked carefully for bore, etc. My webs had areas where there was obvious movement. I'm having only two shuffle pins placed in the middle.

Good pictures - I'm doing a similar rebuild using two engines and EBay.


The magnet test for headstud inserts is what my machinist used to quickly answer that question.

[dtw]

Originally Posted by jaybird840

Bearings measure 2.46 - 2.50 mm. or .096-.097" What do you think?

Agree w/NMT. Those should be standard/standard. The case bore is about 62mm, and the main bearing bore is about 57mm, so half the difference is right around 2.5mm. Right on the money with your measurements. If your bore were larger or your crank were smaller (or both), your bearings would need to be bigger.

Also, the factory 'symbol' stamped on the bearing suggests this is the original set of bearings.

Are you up to speed on the care and feeding of mag 911 engine cases? You'll need to take (or ship) the case to someone who is very familiar with the measuring/qualifying and servicing of these cases.

[jaybird840]

Yep, it's being boxed up with the heads and shipped to CGarr for measurement/machine work.

[jaybird840]

Disassembly is complete!!!! Now, since I don't want to send Craig a filthy case to work on, how is the best way to clean the empty case? I've heard so many horror stories about media blasting clogging the oil passages that I know better than to do that. Can I just submerge the whole side of the case in a pan of Diesel and go to town with a brush? I just want to make sure that I don't do anything to potentially clog or get grit into my oil passages that I later can't get out. As always, your thoughts are appreciated!!! ONWARD TO REASSEMBLY!!

[Flieger]

Check out this thread Media Blasting Heads?....Input Needed

Looks like an ultrasonic cleaning cabinet with water, mild detergent, and some citrus cleaner is a good way to clean parts without damage.

Soda blasting seems to be more of a fine cleaning than other media like sand.

[jaybird840]

Well.... good news today from the machine shop. I just got back from having my cylinders measured, and they all have less than .001" taper (most were around 0.0005"). So it looks like they're good candidates for the scotchbrite/re-ring treatment. I still need to measure the top ring gap to make sure they're within spec, but most everything else has had almost no wear. I was asking the machinist about parts cleaning--like if they had a soda blaster--and he recommended a high pressure parts washer that they have. I asked if it was safe for aluminum/magnesium, and he said it was completely non-caustic. Anyone have experiences--good or bad? The box with the case and heads is on the porch waiting for FedEx pickup. The goals for the week are to get the cams/lifters out to John Dougherty for inspection and regrinding. Also, I hope to get the rods off the crank, and have the crank polished and measured. I'm going to let the local machinist measure the rods as well..... More later!

[jaybird840]

OK Gang,
Here is a pic of one of my main journals--do I really need to strip the crank and have it micropolished? I set the crank up on the flywheel to start stripping it down. Here again, I find myself asking... is this really necessary? From your comments, the main bearings had negligible wear. When I spin the rods on the crank, they are literally buttery smooth. No wiggle, no slop. I'm beginning to wonder how many miles this motor had on it since the rebuild. Your thoughts are always welcome....

[jaybird840]

Hi All,
Well, things are finally picking up steam again toward reconstruction. I am at the stage where I need to have the rotating assembly balanced prior to sealing up the short block. Here are my questions.... I'm using an early 911 flywheel. How many alignment pins are there supposed to be on the flywheel. The pressure plate and the flywheel have holes for three pins, but I have only two. You can see the two pins at approximately 5 and 9 o'clock in the photo. Maybe the machine shop lost one when they pulled them out to surface the flywheel??? See pic.


Second, do I need to install the "ring" from the later model flywheel under the bolts? There is a depression for this "ring" under the bolts on the 2.7 flywheel. There is no such depression on the early flywheel. Do I need washers under the bolts?



Last, what type of bolts do I need to use to secure the pressure plate to the flywheel? Will standard grade 8 steel work?

Thanks tons, guys!!!

--jaybird

[jaybird840]

We're underway again!!! I picked up my freshly balanced rotating assembly last friday. At last, all the machine work is done. I finally got to pull the trigger on the rebuild kit that had been sitting in my pelican parts shopping cart for six months. I told myself that I wouldn't order anything for the rebuild until it was time for reassembly. Blew the whole wad this morning--to the tune of $1500 in parts. I'll try to post some pics of the reassembly once I get underway late next week. See you all soon!!

[jpnovak]

Nice Jay, where did you get the balancing done? Was it local?

I guess I need to speed up my assembly. I still have a transmission to complete after the motor is done.